Add shell based test harness

This allows you to simulate one or more simultaneously running mgmt
processes. It should be easy to use by following the test cases provided.

test.sh

@@ -19,6 +19,5 @@ go vet && echo PASS
 # do these longer tests only when running on ci
 if env | grep -q -e '^TRAVIS=true$' -e '^JENKINS_URL='; then
 	go test -race
-	echo running go vet
-	go vet && echo PASS
+	./test/test-shell.sh
 fi